scholarly journals Acromioclavicular Joint Stabilization: A Biomechanical Study of Bidirectional Stability and Strength

2019 ◽  
Vol 7 (4) ◽  
pp. 232596711983675 ◽  
Author(s):  
Patrick Hislop ◽  
Kentaro Sakata ◽  
David C. Ackland ◽  
Robert Gotmaker ◽  
Matthew C. Evans
Keyword(s):  
Cyclic Loading ◽  
Laboratory Study ◽  
Vertical Plane ◽  
Joint Capsule ◽  
Ac Joint ◽  
Treatment Groups ◽  
Mode Of Failure ◽  
Load To Failure ◽  
Horizontal Stability ◽  
Group A

Background: It is important to restore horizontal and vertical stability to the acromioclavicular (AC) joint when treating dislocations of this joint. Most surgical stabilization techniques of the AC joint have primarily addressed the coracoclavicular ligament complex; however, these techniques may not satisfactorily restore horizontal stability to the AC joint. Purpose: To evaluate the strength and bidirectional stability of 3 AC joint stabilizing techniques in a cadaveric model. Study Design: Controlled laboratory study. Methods: A total of 24 cadaveric shoulders were randomly allocated to 3 treatment groups. For each group, a standardized AC joint stabilizing procedure was performed, and the specimens were potted for mechanical testing. The following reconstruction techniques were used: a single clavicular tunnel for group A, a double clavicular tunnel for group B, and a double clavicular tunnel plus suture fixation across the AC joint for group C. The specimens underwent cyclic loading in the horizontal and vertical planes and then load to failure. Eight control specimens also underwent cyclic loading in both planes. Construct stiffness during cyclic loading, change in displacement after cyclic loading in both planes, load to failure in the vertical plane, and mode of failure were evaluated, and stiffness was compared among the treatment groups as well as with a control group. Results: There was a decrease in joint stiffness for all groups, including controls, during the cyclic loading. Compared with controls, all 3 treatment groups demonstrated equivalent stiffness and displacement in the vertical plane. In the horizontal plane, all 3 treatment groups demonstrated decreased stiffness, increased displacement, or both when compared with controls. When groups were compared, no treatment arm proved superior regarding stiffness or displacement in either plane. Load-to-failure testing of the 3 treatment groups in the vertical plane demonstrated construct strength and stiffness comparable with reports for the native AC joint. The mode of failure was predominantly fracture at the point of fixation to the testing apparatus. Conclusion: There was no difference in bidirectional strength and stability between the single– and double–clavicular tunnel techniques of coracoclavicular reconstruction. The addition of a stabilizing suture across the AC joint does not improve horizontal stability in the absence of repair of the AC joint capsule and deltotrapezial fascia. Clinical Relevance: This laboratory study provides further evidence of the importance of the AC joint capsule and associated soft tissues in affording horizontal stability to that joint. Information from this and subsequent studies utilizing a bidirectional model can influence the choice of surgical procedure in the clinical treatment of AC joint dislocations.

Effects of Allogenic Dermal Fibroblasts on Rotator Cuff Healing in a Rabbit Model of Chronic Tear

2018 ◽  
Vol 46 (8) ◽  
pp. 1901-1908 ◽  
Author(s):  
Jieun Kwon ◽  
Yun Hee Kim ◽  
Sung-Min Rhee ◽  
Tae In Kim ◽  
Jimin Lee ◽  
...  
Keyword(s):  
Rotator Cuff ◽  
Laboratory Study ◽  
Bone Healing ◽  
Rabbit Model ◽  
Dermal Fibroblasts ◽  
The Other ◽  
Histological Evaluation ◽  
Load To Failure ◽  
Group A ◽  
Group B

Background: The failure of rotator cuffs to heal after repair is an unresolved surgical issue. There have been substantial efforts, including the use of biological supplements, to enhance tendon healing. Dermal fibroblasts are a good candidate for tendon tissue engineering because they are similar to the tenocytes used for collagen synthesis. In addition, they are easily accessible because autologous dermal fibroblasts can be obtained from individual skin without major skin defects and allogenic dermal fibroblasts (ADFs) have already been commercialized in the field of skin engineering. Purpose: To determine the effects of dermal fibroblasts on tendon-to-bone healing in a rabbit model of a chronic rotator cuff tear. Study Design: Controlled laboratory study. Methods: A total of 33 rabbits were randomly allocated into 3 groups (n = 11 each). Supraspinatus tendons were detached and left for 6 weeks to establish a chronic rotator tear model. Torn tendons were repaired in a transosseous manner with the injection of 5 × 106 ADFs with fibrin in group A, fibrin only in group B, and saline only in group C. At 12 weeks after repair, the mechanical test and histological evaluation were performed. Results: Seven rabbits died before the evaluation (1 in group A, 2 in group B, 4 in group C). In the final evaluation, the mean ± SD load to failure was 48.1 ± 13.3 N/kg for group A, 34.5 ± 8.9 N/kg for group B, and 31.1 ± 8.3 N/kg for group C, and group A showed significantly higher load-to-failure values than the other groups ( P = .011). The midsubstance tear rate, which presented stronger tendon-to-bone healing than insertional tear, was 50.0% in group A, 22.2% in group B, 28.6% in group C, but the differences were not statistically significant ( P = .413). In the histological evaluation, group A showed greater collagen fiber continuity and better orientation than the other groups. Conclusion: This controlled laboratory study verified, on the basis of biomechanics and histology, the potential for the use of ADFs in rotator cuff healing. The current results suggest a new biological supplement to increase the rate of rotator cuff healing. Clinical Relevance: The most important finding of this study was the potential for a new biological supplement to enhance rotator cuff healing—a continuing challenge.

scholarly journals Novel implant-free loop Tenodesis vs. simple Tenotomy of the long biceps tendon - a biomechanical investigation

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Maximilian Kerschbaum ◽  
Andreas Voss ◽  
Christian Pfeifer ◽  
Isabella Weiss ◽  
Agnes Mayr ◽  
...  
Keyword(s):  
Biceps Tendon ◽  
Maximum Load ◽  
Study Groups ◽  
Displacement Curve ◽  
The Novel ◽  
Shoulder Joints ◽  
Biomechanical Investigation ◽  
Mode Of Failure ◽  
Load To Failure ◽  
Group A

Abstract Background Simple tenotomy and anchor tenodesis are commonly used in treatment of long biceps tendon (LHB) pathologies. The tenotomy can result in biceps distalization or cosmetic deformities. A novel loop Tenodesis Technique (LTD) could prevent a distalization of the biceps muscle without the risk of implant associated complications. The purpose of this study was to investigate the biomechanical aspects of the novel LTD compared to a standard tenotomy of the LHB. It has been hypothesized that the novel technique will show biomechanical superiority in terms of resistance and distalization. Methods Seven paired adult human cadaveric shoulder joints were assigned to one of the two study groups: Loop tenodesis (LTD); simple tenotomy (STT). In both groups load-to-failure testing was performed. The load-displacement curve was used to determine the maximum load (N), the degree of distalization of the LHB (mm) and the stiffness (N/mm). Additionally, the mode of failure was registered. Results The LTD group achieved a significantly higher ultimate load to failure (LTD: 50.5 ± 12.5 N vs. STT: 6.6 ± 3.9 N; p = 0.001). Significantly less distalization of the tendon could be detected for the LTD group (LTD: 8 ± 2.3 mm vs. STT: 22.4 ± 2.4 mm; p = 0.001). Stiffness was 7.4 ± 3.9 N/mm for the LTD group and 0.23 ± 0.16 N/mm for the STT group (p = 0.001). In all specimens of the LTD group a tendon rupture was found as mode of failure, while the STT group failed because of pulling out the LHB through the bicipital groove. Conclusion The novel loop Tenodesis Technique shows biomechanically higher stability as well as less distalization compared to a simple tenotomy of the long biceps tendon.

scholarly journals Longer stitch interval in the Krackow stitch for tendon graft fixation leads to poorer biomechanical property

2018 ◽  
Vol 26 (3) ◽  
pp. 230949901879951 ◽  
Author(s):  
Chih-Kai Hong ◽  
Cheng-Li Lin ◽  
Fa-Chuan Kuan ◽  
Ping-Hui Wang ◽  
Ming-Long Yeh ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Ultimate Load ◽  
Tendon Graft ◽  
Biomechanical Study ◽  
Graft Fixation ◽  
Biomechanical Property ◽  
Cross Sectional ◽  
Mode Of Failure ◽  
Load To Failure ◽  
Post Hoc

Purpose: The purpose of this study was to analyze the effects of different intervals between stitch throws on tendon graft fixation with the Krackow stitch. Methods: Forty-four porcine flexor profundus tendons were randomly divided into four groups of 11 specimens each. The Krackow stitch with various stitch intervals (2.5, 5.0, 7.5, and 10.0 mm) were evaluated, and named the K-2.5, K-5.0, K-7.5, and K-10.0 groups, respectively. A braided nonabsorbable suture was used to complete each suture-tendon construct. All specimens were pretensioned to 100 N for three cycles, cyclically loaded from 50 to 200 N for 200 cycles, and then finally loaded to failure. Elongation after cyclic loading, ultimate load to failure, and the mode of failure were recorded. Results: There were significant differences in elongation after cyclic loading among the K-2.5 (31% ± 5%), K-5.0 (32% ± 4%), K-7.5 (34% ± 5%), and K-10.0 (41% ± 8%) groups ( p = 0.004); the post hoc analysis showed significantly smaller values in the K-2.5 and K-5.0 groups than in the K-10.0 group ( p = 0.002 and 0.003, respectively). The stitch interval was correlated with elongation after cyclic loading ( r = 0.52, p < 0.001). Ultimate loads to failure and cross-sectional area were not significantly different across the four groups. Conclusion: The Krackow stitch with stitch intervals of 2.5 and 5.0 mm had significantly smaller elongation after cyclic loading than with an interval of 10.0 mm in this porcine biomechanical study. The stitch interval was moderately correlated with elongation after cyclic loading.

scholarly journals Biomechanical evaluation of simulated feline patellar fracture repairs

2017 ◽  
Vol 30 (02) ◽  
pp. 125-130
Author(s):  
Sorrel Langley-Hobbs ◽  
John Tarlton ◽  
Mark Longley
Keyword(s):  
Soft Tissues ◽  
Patellar Fracture ◽  
Video Capture ◽  
Mode Of Failure ◽  
Load To Failure ◽  
Gap Opening ◽  
Group A ◽  
Biomechanical Evaluation ◽  
Group B ◽  
Group D

SummaryObjective: To investigate four techniques for stabilization of feline patellar fracture.Methods: Feline cadaveric stifles with simulated patellar fracture were stabilized with one of four techniques: Group A - circumferential wire, group B - figure-of-eight wire, group C - combined figure-of-eight and circumferential wire, group D - pin and tension band wire. All repairs were subjected to a period of cyclic loading prior to load to failure testing. Experiments were recorded by video capture to determine load at failure and failure mode. Failure was defined as an opening of the fracture gap of 3 mm.Results: Mean fracture gap opening (±SD) during peak loading after 1000 cycles was: group A with 1.66 mm (± 0.69), group B with 1.01 mm (± 0.45), group C with 0.81 mm (± 0.58), and group D with 0.65 mm (± 0.54). Groups C and D had significantly lower mean fracture gap opening after 1000 cycles when compared to group A (p <0.05). Mean loads (± SD) at failure were: group A with 171.4 N (± 62.2), group B with 208.7 N (± 20.7), group C with 288.2 N (± 62.5), and group D with 219.5 N (± 48.0). Group C had significantly higher mean load to failure than all other groups (p <0.05). There was no difference between other groups. In groups A, B and C the principle mode of failure was wire elongation and tearing of sutures through the retinaculae and periarticular soft tissues. In group D, the principle mode of failure was the pin pulling through the bone of the distal fragment.Conclusions: Combined figure-of-eight and circumferential wires may be useful for treatment of transverse feline patellar fracture.

scholarly journals The Role of the Acromioclavicular Ligament in Acromioclavicular Joint Stability: A Cadaveric Biomechanical Study

2021 ◽  
Vol 9 (2) ◽  
pp. 232596712098294
Author(s):  
Shimpei Kurata ◽  
Kazuya Inoue ◽  
Hideo Hasegawa ◽  
Takamasa Shimizu ◽  
Akio Iida ◽  
...  
Keyword(s):  
Biomechanical Study ◽  
Joint Capsule ◽  
Joint Stability ◽  
Ac Joint ◽  
Rockwood Classification ◽  
Posterior Displacement ◽  
Horizontal Stability ◽  
Fresh Frozen ◽  
Trapezoid Ligament ◽  
Stage 1

Background: Acromioclavicular (AC) joint dislocation is evaluated using the radiologically based Rockwood classification. The relationship between ligamentous injury and radiological assessment is still controversial. Purpose/Hypothesis: To investigate how the AC ligament and trapezoid ligament biomechanically contribute to the stability of the AC joint using cadaveric specimens. The hypothesis was that isolated sectioning of the AC ligament would result in increased instability in the superior direction and that displacement >50% of the AC joint would occur. Study Design: Controlled laboratory study. Methods: Six shoulders from 6 fresh-frozen cadavers were used in this study. Both the scapula and sternum were solidly fixed on a customized wooden jig with an external fixator. We simulated distal clavicular dislocation with sequential sectioning of the AC and coracoclavicular (CC) ligaments. Sectioning stages were defined as follows: stage 0, the AC ligament, CC ligament, and AC joint capsule were left intact; stage 1, the anteroinferior bundle of the AC ligament, joint capsule, and disk were sectioned; stage 2, the superoposterior bundle of the AC ligament was sectioned; and stage 3, the trapezoid ligament was sectioned. The distal clavicle was loaded with 70 N in the superior and posterior directions, and the magnitudes of displacement were measured. Results: The amounts of superior displacement averaged 3.7 mm (stage 0), 3.8 mm (stage 1), 8.3 mm (stage 2), and 9.5 mm (stage 3). Superior displacement >50% of the AC joint was observed in stage 2 (4/6; 67%) and stage 3 (6/6; 100%). The magnitudes of posterior displacement were 3.7 mm (stage 0), 3.7 mm (stage 1), 5.6 mm (stage 2), and 9.8 mm (stage 3). Posterior displacement >50% of the AC joint was observed in stage 3 (1/6; 17%). Conclusion: We found that the AC ligaments contribute significantly to AC joint stability, and superior displacement >50% of the AC joint can occur with AC ligament tears alone. Clinical Relevance: The AC ligament plays an important role not only in horizontal stability but also in vertical stability of the AC joint.

scholarly journals Suture-bridge technique for tibial avulsion fractures of the posterior cruciate ligament - a biomechanical comparison

2019 ◽  
Vol 7 (6_suppl4) ◽  
pp. 2325967119S0022
Author(s):  
Lukas Willinger ◽  
Lucca Lacheta ◽  
Constantin von Deimmling ◽  
Jan Lang ◽  
Andreas Imhoff ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Cruciate Ligament ◽  
Initial Stiffness ◽  
Avulsion Fractures ◽  
Suture Bridge ◽  
Load To Failure ◽  
Group A ◽  
Group B ◽  
Pcl Avulsion ◽  
Suture Bridge Technique

Aims and Objectives: Tibial posterior cruciate ligament (PCL) avulsion fractures require surgical fixation in order to provide primary stability and adequate bone healing. Small fragments are common and comprise the risk to fracturing during screw fixation. Therefore, a suture-bridge configuration was developed to fixate small and multifragment fractures without the need of fragment drilling. The purpose of this study was to analyze the biomechanical properties of the suture-bridge technique compared to a well-established transtibial cortical suspension technique concerning cyclic elongation, stiffness and ultimate failure load. It was hypothesized that the suture bridge technique shows lower cyclic elongation and higher load to failure force compared to a cortical suspension button fixation. Materials and Methods: Nine fresh-frozen human cadaveric knees were biomechanically tested using an industrial testing machine (Zwick/Roell Amsler HC 10, Ulm). A standardized bony avulsion fracture (15 x 10 x 4 mm) of the tibial PCL insertion was generated. Two different techniques were used for fixation: A) 4x suture-bridge configuration (3 SwiveLock anchors, FiberTape, Arthrex Inc.) and B) 5x transtibial cortical suspension button fixation (FiberTape, Arthrex Inc). Cyclic loading was applied in 90° of flexion 500 times (10 to 100 N) to determine elongation, initial stiffness and load to failure. Students t-test for unpaired samples were used to calculate the difference of means (SPSS statistics software version 21). Statistical significance was set at a p value of < 0.05. Results: Suture-bridge technique resulted in a significant lower elongation (4.5 ± 2.9 mm) than transtibial cortical suspension button technique (11.9 ± 3.1 mm, p<0.01). Load of failure testing exhibited 319.8 ± 79.7 N in Group A and 232.6 ± 108.2 N in Group B (p=0.21). The initial stiffness at the beginning of cyclic loading was 45.0 ± 7.7 N/mm in Group A und 40.9 ± 10.0 N/mm in Group B (p=0.52). Conclusion: The novel PCL suture-bridge technique provides a significant lower construct elongation during cyclic loading and a trend towards higher load to failure in comparison to cortical suspension button fixation. As a clinical consequence, suture-bridge technique should be considered to fix small PCL avulsion fractures at the tibial insertion site.

Comparison of All-Inside Meniscal Repair Devices With Matched Inside-Out Suture Repair

2011 ◽  
Vol 39 (12) ◽  
pp. 2634-2639 ◽  
Author(s):  
Claudio Rosso ◽  
Konstantin Kovtun ◽  
William Dow ◽  
Brett McKenzie ◽  
Ara Nazarian ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Meniscal Repair ◽  
Suture Repair ◽  
Initial Displacement ◽  
Displacement Response ◽  
Significant Difference ◽  
Mode Of Failure ◽  
Load To Failure ◽  
Suture Failure ◽  
Inside Out

Background: All-inside meniscal repairs are performed with increasing frequency because of the availability of newly developed devices. A comparison of their biomechanical characteristics may aid physicians in selecting a method of meniscal repair. Hypothesis: All-inside meniscal repairs will be superior to their inside-out controls in response to cyclic loading and load-to-failure testing. Study Design: Controlled laboratory study. Methods: Sixty-six bucket-handle tears in matched porcine menisci were repaired using the Ultra FasT-Fix, Meniscal Cinch, Ultrabraid No. 0, and FiberWire 2-0 sutures. Initial displacement, cyclic loading (100, 300, and 500 cycles), and load-to-failure testing were performed. The displacement, response to cyclic loading, and mode of failure were recorded. The stiffness was calculated. Results: The Meniscal Cinch demonstrated a significantly higher initial displacement than the other methods tested ( P = .04). No significant difference was found among the methods in response to cyclic loading. The inside-out FiberWire repair demonstrated the highest load to failure (120.8 ± 23.5 N) and was significantly higher than both the Meniscal Cinch (64.8 ± 24.1 N, P < .001) and the Ultra FasT-Fix (88.3 ± 14.3 N, P = .002). It was not significantly higher than the inside-out Ultrabraid suture repair (98.8 ± 29.2 N). The inside-out FiberWire repair had the highest stiffness (28.7 ± 7.8 N/mm). It was significantly higher than the Meniscal Cinch (18.0 ± 8.8 N/mm, P = .01). The most common mode of failure in all methods was suture failure. Conclusion: An inside-out suture repair affords surgeons the best overall biomechanical characteristics of the devices tested (initial displacement, response to cyclic loading, and load to failure). For an all-inside repair, the Ultra FasT-Fix reproduces the characteristics of its matched inside-out suture repair more closely than the Meniscal Cinch. Clinical Relevance: Inside-out sutures and all-inside devices have similar responses to cyclic loading.

Quantitative and Qualitative Surgical Anatomy of the Acromioclavicular Joint Capsule and Ligament: A Cadaveric Study

2021 ◽  
pp. 036354652199550
Author(s):  
Philip-C. Nolte ◽  
Joe J. Ruzbarsky ◽  
Kaare S. Midtgaard ◽  
Kira K. Tanghe ◽  
Bryant P. Elrick ◽  
...  
Keyword(s):  
Surgical Anatomy ◽  
Joint Capsule ◽  
Ac Joint ◽  
Measuring Device ◽  
Mean Values ◽  
Precise Knowledge ◽  
Horizontal Stability ◽  
Fresh Frozen ◽  
The Mean ◽  
Superior Portion

Background: The acromioclavicular (AC) capsule and ligament have been found to play a major role in maintaining horizontal stability. To reconstruct the AC capsule and ligament, precise knowledge of their anatomy is essential. Purpose/Hypothesis: The purposes of this study were (1) to determine the angle of the posterosuperior ligament in regard to the axis of the clavicle, (2) to determine the width of the attachment (footprint) of the AC capsule and ligament on the acromion and clavicle, (3) to determine the distance to the AC capsule from the cartilage border of the acromion and clavicle, and (4) to develop a clockface model of the insertion of the posterosuperior ligament on the acromion and clavicle. It was hypothesized that consistent angles, attachment areas, distances, and insertion sites would be identified. Study Design: Descriptive laboratory study. Methods: A total of 12 fresh-frozen shoulders were used (mean age, 55 years [range, 41-64 years]). All soft tissue was removed, leaving only the AC capsule and ligament intact. After a qualitative inspection, a quantitative assessment was performed. The AC joint was fixed in an anatomic position, and the attachment angle of the posterosuperior ligament was measured using a digital protractor. The capsule and ligament were removed, and a coordinate measuring device was utilized to assess the width of the AC capsule footprint and the distance from the footprint to the cartilage border of the acromion and clavicle. The AC joint was then disarticulated, and the previously marked posterosuperior ligament insertion was transferred into a clockface model. The mean values across the 12 specimens were demonstrated with 95% CIs. Results: The mean attachment angle of the posterosuperior ligament was 51.4° (95% CI, 45.2°-57.6°) in relation to the long axis of the entire clavicle and 41.5° (95% CI, 33.8°-49.1°) in relation to the long axis of the distal third of the clavicle. The mean clavicular footprint width of the AC capsule was 6.4 mm (95% CI, 5.8-6.9 mm) at the superior clavicle and 4.4 mm (95% CI, 3.9-4.8 mm) at the inferior clavicle. The mean acromial footprint width of the AC capsule was 4.6 mm (95% CI, 4.2-4.9 mm) at the superior side and 4.0 mm (95% CI, 3.6-4.4 mm) at the inferior side. The mean distance from the lateral clavicular attachment of the AC capsule to the clavicular cartilage border was 4.3 mm (95% CI, 4.0-4.6 mm), and the mean distance from the medial acromial attachment of the AC capsule to the acromial cartilage border was 3.1 mm (95% CI, 2.9-3.4 mm). On the clockface model of the right shoulder, the clavicular attachment of the posterosuperior ligament ranged from the 9:05 (range, 8:00-9:30) to 11:20 (range, 10:00-12:30) position, and the acromial attachment ranged from the 12:20 (range, 11:00-1:30) to 2:10 (range, 13:30-14:40) position. Conclusion: The finding that the posterosuperior ligament did not course perpendicular to the AC joint but rather was oriented obliquely to the long axis of the clavicle, in combination with the newly developed clockface model, may help surgeons to optimally reconstruct this ligament. Clinical Relevance: Our results of a narrow inferior footprint and a short distance from the inferior AC capsule to cartilage suggest that proposed reconstruction of the AC joint capsule should focus primarily on its superior portion.

Biomechanical Comparison of Anatomic and Extra-Anatomic Reconstruction Techniques Using Local Grafts for Chronic Instability of the Acromioclavicular Joint

2018 ◽  
Vol 46 (8) ◽  
pp. 1927-1935 ◽  
Author(s):  
Malo Le Hanneur ◽  
Andrew Thoreson ◽  
Damien Delgrande ◽  
Thibault Lafosse ◽  
Jean-David Werthel ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Primary Stability ◽  
Hydraulic Testing ◽  
Anatomic Reconstruction ◽  
Graft Material ◽  
Ac Joint ◽  
Chronic Instability ◽  
Coracoacromial Ligament ◽  
Load To Failure ◽  
Anterior Posterior

Background: Anatomic reconstruction techniques are increasingly used to address cases of acromioclavicular (AC) joint chronic instability. These usually involve an additional surgical site for autograft harvesting or an allograft. Purpose: To describe a triple-bundle (TB) anatomic reconstruction using on-site autografts, the semiconjoint tendon (SCT) and the coracoacromial ligament (CAL), and compare its primary stability to the native AC joint ligamentous complex and to a modified Weaver-Dunn (WD) reconstruction. Study Design: Controlled laboratory study. Methods: Intact AC joints of 12 paired cadaveric shoulders were tested for anterior, posterior, and superior translations under cyclic loading with a servo-hydraulic testing system. One shoulder from each pair was randomly assigned to the TB group, where 2 SCT strips were used to reconstruct the coracoclavicular ligaments while the distal end of the CAL was transferred to the distal extremity of the clavicle to reconstruct the AC ligaments; the other shoulder received a modified WD reconstruction. After reconstruction, the same translational testing was performed, with an additional load-to-failure test in the superior direction. Results: In both the TB and the WD groups, no significant differences were found before and after reconstruction in terms of joint displacements after cyclic loading, in all 3 directions. Compared with the WD reconstruction, the TB repair resulted in significantly lower displacements in both the anterior (ie, 2.59 ± 1.08 mm, P = .011) and posterior (ie, 10.17 ± 6.24 mm, P = .014) directions, but not in the superior direction. No significant differences were observed between the 2 reconstructions during the load-to-failure testing, except for the displacement to failure, which was significantly smaller (ie, 5.34 ± 2.97 mm) in the WD group ( P = .037). Conclusion: Anterior, posterior, and superior displacements after an anatomic reconstruction of the AC joint complex using the SCT and CAL as graft material were similar to those of native AC joints and significantly smaller in the axial plane than those of AC joints after a WD repair. Clinical Relevance: An anatomic reconstruction is achievable using the CAL and the SCT as on-site graft materials, providing satisfactory initial stability and thereby allowing earlier mobilization.

Hormonal stimulation and some risk factors studied to improve bovine pregnancy rate at the Coastal areas of Barisal district of Bangladesh

2018 ◽  
Vol 52 (1-4) ◽  
pp. 22-30
Author(s):  
A K Paul ◽  
S M T Rahman
Keyword(s):  
Pregnancy Rate ◽  
Coastal Region ◽  
Hormonal Treatment ◽  
Coastal Areas ◽  
Pregnancy Rates ◽  
Hormonal Stimulation ◽  
Crossbred Cows ◽  
Treatment Groups ◽  
History Of ◽  
Group A

Hormonal treatment of cows at the coastal region of Barisal district of Bangladesh was performed to assess the improvement of pregnancy rate. A total of 100 cows and heifers with irregular history of cyclicity were selected randomly and divided into five treatment groups. The groups were A (treated with anthelmintic), B (treated with anthelmintic, vitamin ADE and multivitamin powder), C (treated with PGF2α), D (treated with GnRH) and E (treated with GnRH and PGF2α). Each group comprised of 20 animals. The age, breed and parity of experimental cows were considered during treatment. In the study, the cows treated with both GnRH and PGF2α (group E) showed significantly (p<0.05) higher estrus (80%) and pregnancy rate (60%) than that of group A, B, C and D. The overall estrus rates of local and crossbred cows were 64% and 70%, respectively and the pregnancy rates were 40 and 52%, respectively. The crossbred cows responded significantly (p<0.05) to hormonal treatment than that of local cows. Parity-2 cows showed higher estrus sign than that of other parities. However, the pregnancy rates were higher significantly (p<0.05) in parity-2 and parity ≥4 cows than that of parity-0, parity-1 and parity-3 cows. The pregnancy rate was also found higher in case of 4 to <5 years old cows than that of 2 to <3, 3 to <4, 5 to <6, and ≥6 years old. It may conclude that the hormonal regimen increases the pregnancy rate as well as decreases the undesired waiting of estrus and conception. Further study with more sample size will reveal the more effective treatment for cows at the coastal areas of Bangladesh.

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